Luck, defense, and positioning failed Aaron Bummer in 2021

As part of my 2021 review of White Sox pitchers, I mentioned that Aaron Bummer‘s 2021 season compared unfavorably to his 2019 campaign in part because of a major decrease in double-play ground balls and an increase in unfortunate singles yielded by dribblers. In addition, I suggested the White Sox infield positioning should be reviewed to determine whether it contributed to Bummer’s rough luck.

The MLB Film Room allowed me to watch all 27 ground ball singles allowed by Aaron Bummer in 2021 (he allowed 42 hits in total). For health reasons, no one else should do this. After collecting myself from re-witnessing these traumatic events, I categorized them.

Dribblers (count = 6)

These are essentially ground balls on non-bunts that weren’t hit hard enough to get to a fielder on time. You can watch all six in the below if you have a high pain tolerance. I included one in here in which Bummer deflected a high chopper with his glove.

There’s nothing Bummer or the defense can do about these. It’s just bad fortune, and it hit Bummer more often than most pitchers this season.

Defensive Failures (count = 3)

None of these are easy plays (otherwise they’d be errors), but these are spots when Bummer was let down by his infield. Even if one were to argue that there was nothing the fielders could do, they’d arguably slide up into the “dribblers” group.

That’s one-third of Bummer’s ground ball singles that involved extremely weak contact. The vast majority of the remaining 18 involved either hard-hit balls or finding holes around reasonably-positioned fielders (most often righties slapping the ball to the second baseman’s left).

Likely defensive positioning issues (count = 3)

However, there were a few instances where it looked like the positioning of the infielders could have been improved. It’s known that Tony La Russa’s White Sox employ significantly fewer infield shifts than most teams in the league, where a shift is defined as having at least three infielders on the same side of second base. This year, there was a slight negative correlation between shifting and opposing batting average.

The correlation isn’t all that strong because both luck and the quality of fielders matter a great deal. However, three of the ground ball singles Bummer allowed might have been preventable with more logical positioning.

1) Michael Brantley, July 16

Brantley is not a pure pull hitter, but his ground ball spray chart against left-handed pitchers (below) shows a significant bias to the pull side.

It’s easiest to play a defensive shift against a lefty when there are no runners on second or third base. In those situations, opposing defenses chose to shift 50 percent of the time against Brantley in 2021. Even if the shortstop isn’t on the first-base side of second, there’s a strong argument to at least push the shortstop close to second base.

Here’s a video of the play:

Brantley doesn’t hit the ball hard at all, but it makes it to the outfield grass. Whether improved positioning would have prevented this depends on just how far over Tim Anderson shifted. However, here’s what I consider to the be the critical frame from the play:

By this point, Anderson and Leury Garcia have already taken a few steps in the direction of second. This is simply too much space in the middle of the field against Brantley’s batted ball profile.

2) Austin Meadows, June 16th.

Meadows is more of a classic pull-hitting lefty, and at least on grounders, his batted ball profile looks similar against lefties and righties. Below is his ground ball spray chart against all pitchers from this year.

On the season, teams shifted on Meadows 90% of the time with no runners on 2nd or 3rd. Yet, the Sox elected not to on this particular play. Here was the result:

This ball is hit pretty hard, and maybe it gets through anyway. However, it rolls through the infield right around Tim Anderson’s average starting point when the White Sox shift against a lefty, as shown below.

There’s a strong chance that an infield shift would have stopped this one, and based on the way the rest of the league defends Meadows, a great argument that one should have been used.

3) Willie Calhoun, April 23

Calhoun’s ground ball spray chart is slightly less extreme than Meadows’. Still, there’s a heavy concentration up the middle and to the pull side.

Teams elected to shift on Calhoun approximately 80 percent of the time with no one on second or third base. Again, in this particular plate appearance, the White Sox did not. The result was largely the same as for the Meadows play above: the ball went right around where Anderson would be playing in an infield shift formation.

* * * * *

The above is why I consider Aaron Bummer to still be a top-flight relief pitcher heading into 2022. He made a lot of his own mess by upping his walk rate this season, but the type of contact Bummer allowed is just not all that dangerous. Further, of the 597 guys that threw at least 200 pitches this year, Bummer had just the 238th-best double-play rate, despite inducing more grounders than anyone and a fair number of hitters reaching first base via walks and cheap singles. We’d certainly expect closer to the 15 double plays he got in 2019 than the mere five he collected this year. Even Jace Fry got five in 2021.

An important secondary conclusion is that the White Sox should continue to evaluate their shifting decisions. A running theme of the ALDS was Astros ground balls finding the outfield grass and White Sox ground balls finding Jose Altuve. The above three instances just encapsulate the experience of one relief pitcher (albeit one highly dependent on ground balls); there should be a more thorough review conducted on how often the White Sox’ infield positioning helped or hurt.

To his credit, Rick Hahn gave a reasonable defense of the team’s shifting strategy, stating that the White Sox saved an above-average amount of runs via the shift despite doing it less. That has a lot to do with Tony La Russa correctly foregoing the shift against right-handed batters, which is a tactic that has actually hurt more than it’s helped leaguewide. The White Sox are still well-below average in shifting against left-handed hitters, however, which tends to be more beneficial. Hopefully the Sox will take a good look at this, because it could help the Sox get their relief ace back next season.

Photo credit: Matt Marton-USA TODAY Sports

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